Environmental Application, Fate, Effects, and Concerns of Ionic Liquids: A Review

Abstract

Ionic liquids (ILs) comprise mostly of organic salts with negligible vapor pressure and low flammability that are proposed as replacements for volatile solvents. ILs have been promoted as "green" solvents and widely investigated for their various applications. Although the utility of these chemicals is unquestionable, their toxic effects have attracted great attention. In order to manage their potential hazards and design environmentally benign ILs, understanding their environmental behavior, fate and effects is important. In this review, environmentally relevant issues of ILs, including their environmental application, environmental behavior and toxicity are addressed. In addition, also presented are the influence of ILs on the environmental fate and toxicity of other coexisting contaminants, important routes for designing nontoxic ILs and the techniques that might be adopted for the removal of ILs.

Ionic liquids in enhancing the sensitivity of capillary electrophoresis: Off‐line and on‐line sample preconcentration techniques

“…Under optimum conditions, analysis in less than 12 min with LODs ranged between 0.5 and 5 g/mL was obtained. Other micellar ILs [C 14 MIm]Cl (where [C 14 MIm] is 1-tetradecyl-3-methylimidazolium), [C 14 MIm]Br, and [C 18 MIm]Br were also used [72][73][74] to develop IL-MEKC methods for the preconcentration of methylresorcinol isomers, seven urinary nucleosides, and phenolic compounds. Some improvements in the detection limits of analytes were achieved [74].…”

“…This is due to the fact that the most commercial CE apparatus Correspondence: Professor Deia Abd El-Hady, Department of Chemistry, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia E-mail: deiaabdelhady@yahoo.com, deiaabdelhady@gmail.com Abbreviations: AFMC, analyte focusing by micelle collapse; BF 4 , tetraflouroborate; BGS, background solution; C 2 MIm, 1-ethyl-3-methylimidazolium; C 4 MIm, 1-butyl-3-methylimidazolium; C 6 MIm, 1-hexyl-3-methylimidazolium; C 8 MIm, 1-octyl-3-methylimidazolium; C 12 MIm, 1-dodecyl-3-methylimidazolium; C 14 MIm, 1-tetradecyl-3-methylimidazolium; C 16 MIm, 1-cetyl-3-methylimidazolium; C 16 MPy, 1-cetyl-n-methylpyrrolidinium; CTAB, cetyltrimethylammonium bromide; IL-AFMC, IL-based AFMC; IL, ionic liquid; IL-ATPS, IL-based aqueous two phase system; IL-DLLME, IL-based dispersive liquid-liquid microextraction; IL-MEKC, IL-based MEKC; IL-LPME, IL-based liquid phase microextraction; IL-SDME, IL-based single drop microextraction; MSS, micelle to solvent stacking; MSSB, micelle to solvent boundary; NtfO2, bis(trifluoromethylsulfonyl)imide; PF 6 , hexaflourophosphate; PVBIm, poly(1-vinyl-3-butylimidazolium); SEF, sensitivity enhancement factor are equipped with ultraviolet-visible (UV-Vis) spectrometers having low injection volume and short light path length. It is therefore difficult to determine trace analytes in real samples directly by CE.…”

Layer-by-layer encapsulated nano-emulsion of ionic liquid loaded with functional material for extraction of Cd2+ ions from aqueous solutions

“…Ionic liquids, which are salts that are liquid below 100˚C [1], show great potential [1][2][3] as environmentallyfriendly extraction solvents due to their unique properties, such as negligible vapour pressure, high thermal stability, non-flammability [4]. More specifically, hydrophobic ionic liquids may be used for the separation of metal ions from aqueous solutions and wastewaters, where they can be specifically designed to act as extractors themselves [5] or, more commonly, serve as an extraction medium for active materials, such as crown ethers [6,7] or any other ion-specific extractants [8].…”

Quaternary ammonium nonanoate-based ionic liquids as chemicals for crop protection

“…Efficient use of ILs should compromise high biological activity directed to specific pests with negligible impact on other organisms present in soil or water. General procedures for the synthesis of non-toxic and environmental friendly ILs have been established on the basis of several studies dedicated to this topic [42]. The use of ionic forms of substances commonly present in nature may be an alternative way to lower the toxicity and improve the biodegradability of ILs, since such substances are often characterized by promising properties [40,43].…”